Chandni Chowk (Hindi: चाँदनी चौक, Punjabi:ਚਾਂਦਨੀ ਚੌਂਕ, Urdu: چاندنی چوک) is one of the oldest and busiest markets in central north Delhi, India. The area is the historically important Shahjahanabad between the Lal Qila (The Red Fort) and Fatehpuri Masjid. With the most famous mosque of Delhi Jama Masjid (Delhi) in the vicinity, along with Gurudwara Sis Ganj Sahib, Jain Mandir and a lot of small temples, the place witnesses a genuine cultural harmony.

Chandni Chowk's speciality is the variety of its markets and their Indian-ness. From authentic Indian food, delicacies and sweets of more than 1000 kinds, to sarees with chikan, zaree work. There are lots of narrow lanes with many shops selling books, clothing, shoes and leather goods, electronic and consumer goods and what not. The area, even more so than the rest of the city, is congested. This is also a good area for window shopping. It is the location of the original Haldiram's. A particular local delicacy are the jalebis, which are fried in pure ghee (clarified butter).

Among the famous mosques in Chandni Chowk are Jama Masjid, Fatehpuri Masjid and Sunahari Masjid (literally Golden Mosque). It was from here that Persian emperor Nadir Shah watched the plunder of Delhi in 1739 when more than 30,000 people were killed.